Note: This question is about TES IV: Oblivion, not Skyrim.
Can NPCs or non/semi-aquatic creatures (no 'Water Breathing' ability) drown? (Aquatic creatures have 'Water Breathing' as an ability.)
Also, regardless if they do drown or not, do they come up for air once they're underwater?
(I'm especially curious if this semi-aquatic creature drowns or not, and if it comes up for air..)
Best Answer
Yes, NPCs and creatures can drown.
Based from multiple UESP wiki articles and reports from various Oblivion forums, I found that NPCs and creatures that do not have the 'Water Breathing' ability can drown, and will go up for air once they're underwater (on creatures, this behavior will depend on their AI).
Among those that can't drown are aquatic creatures like slaughterfishes and its different varieties, Undead creatures and Argonian NPCs, which all have the 'Water Breathing' ability. Some Undead creatures have the 'Water Walking' ability, instead of 'Water Breathing'.
Some reports I found from UESP wiki articles (emphasis mine):
From: UESP wiki, "Horses" (Oblivion) article
From: UESP wiki, "Undead" (Oblivion) article
From: UESP wiki, "Guard Uniforms" (how to acquire City Guard uniforms without receiving a large bounty) article
Reports from various forum posts:
From: this Reddit /r/Oblivion comment
From: this UESP 'Oblivion' forum post
From: http://www.uesp.net/wiki/Oblivion_talk:Water_Breathing